Tube bender



1938. A. PARKER v 2,127,185

TUBE BENDER I Filed Sept. 15, 1935 2 Sheets-Shoot 1 Aug. 16, 1938. A.PARKER 2,127,185

TUBE BENDER 7 Filed Sept. 13, 1935 2 Sheets-Sheet 2 Patented Aug. 16,1938 UNITED STATES PATENT OFFICE 11 Claims.

The invention relates to new and useful improvements in a tube bender,and more particularly to a hand-operated tube bender having a radiusblock curved to conform to the curvature to which the tube is to bebent.

An object of the invention is to provide a tube bender wherein thebending arm is provided with a rigid head contactingwith the tube andthe mounting for said bending arm is so constructed that the headthereof is free from contact with the radius block during the bendingoperation.

A further object of the invention is to provide a tube bender of theabove type wherein the supporting arm for the radius block is soattached to said block that it may be shifted to different set positionsrelative thereto.

A still further object of the invention is to provide a. tube bender ofthe above type with a clamping vise for holding the tube in a setposition during bending, which clamping vise may be quickly releasedfrom the tube and the clamping member thereof positioned so as to permitthe tube to be moved laterally into the vise.

A still further object of the invention is to provide a tube bender ofthe above type wherein the bending arm and the rigid head carriedthereby may be turned to a position so as to pemiit the tube to beinserted between the radius block and tbse bending head by the lateralmovement of the tu These and other objects will in part be obvious andwill in part be hereinafter more fully disclosed.

In the drawings- Figure 1 is a front view of a bending device embodyingthe improvements, showing in full lines a tube in place for bending andin broken lilies the bending arm moved for curving the tu c;

Fig. 2 is a rear view of the bending device showing the tube in positionin full lines for bending and in dotted lines the bending arm and headmoved for curving the tube to conform to the radius block;

Fig. 3 is a view partly in side elevation and partly in section on anenlarged scale, and showing the tube positioned and clamped ready forbendin Fig. 4 is a view on the line 4-4 of Fig. 2, showing in full linesthe vise in position for clamping the tube and in broken lines inposition for releasing the tube;

Fig. 5 is a view partly in plan and partly in section showing theclamping vise in open position and he bending head turned so that thetube to be bent may be inserted in the tube bender by the lateralmovement thereof;

Fig. 6 is a view showing the tube as bent through an arc of degrees andthe lever handle supporting the vise shifted to a different set position.so that the bending operation may be continued; v

Fig. 7 is a. detail in section showing the locking device for holdingthe lever arm in different set positions on the radius block;

Fig. 8 is a transverse sectional view through a portion of the radiusblock and bending head, and

Fig. 9 is a view partly in section showing the bending head positionedfor compounding the pressure exerted upon the tube for bending the same.

The invention has to do with a tube bender which is particularly adaptedfor hand operation and which may be used for bending tubes. The tubebender includes a radius block I which is provided with a face 2 curvedabout the center 3 of the radius block. 'This is the bending face aroundwhich the tube is curved, and it is shaped to conform to the desiredcurvature which is to be given the tube. As illustrated in the drawings,this curved face extends through an arc of approximately degrees. Thecurved face is provided with a recess 4 which extends peripherallythereof and is locatedmidway between the side face of the radius block.This recess is preferably curved to conform to the cross-sectionalcurvature of th'e'tube and serves as-a. seat for the tube and preventslateral movement of the tube in the radius block.

The radius block is extended to the left of the center as viewed in Fig.1, and the upper face 5 of this extension is tangential to the curvedface 2 of the radius block. This upper face 5 is also provided with arecess 4 (see Fig. 4) which is shaped to conform to the recess 4. Thisportion of the radius block constitutes one member of a clamping visewhich holds the tube that is to be bent in a set position on the radiusblock. The

lower face I of the extension of the radius block is likewise recessedso as to form. a seat for the tube and permit the tube to be bent sothat the curved portion thereof extends through an arc of 180 degrees,and the tube ends connected thereto are parallel.

Pivotally mounted on the extension of the radius block is a clampingmember 8. The radius block has spaced lugs 9, 9 formed integraltherewith, and the clamping member 8 is mounted on a pivot pin llextending through said lugs. The

' pin III and is threaded to receive a clamping bolt I2. The clampingbolt I2 is provided with a cross arm i3 which may be utilized forturning the clamping bolt. When the. clamping member is moved to aclosed position, as shown in full lines in Fig. 4, the clamping bolt isthen turned until it is brought'into contact with the shoulder IL Thisserves as an abutment so that the turning of the bolt will cause thetube to be firmly clamped in the vise. The radius block is cut away atl5 just above the shoulder, and when it is desired to release the vise,the clamping bolt is turned so as to withdraw the bolt from con tactwith the shoulder. It is only necessary to retract the bolt a slightdistance from the shoulder in order to permit the end of the bolt tomove into the cutaway i5 and the clamping member-to swing to openposition. This makes a clamping member which is quickly releasable forreleasing the tube so that it can be removed from the bender. When theclamping member 8 of the vise is moved to the open position, as shown inFig. 4, the tube can be moved laterally on to the seat in the radiusblock and does not have to be threaded endwise into the bender.

. Attached to the radius block is a lever arm I'B. Centrally of theradius block is .a pivot stud l1 and this lever arm is mounted on thispivot stu'd forfree swinging movement about the axis thereof. Saidradius block is provided with a stop shoulder i8 which limits themovement of the lever arm l6'in a counter-clockwise direction about thepivot stud. It is also provided with a stop shoulder l9 which limits themovement of the leverarmin a clockwise direction about said pivot stud.Mounted on the lever arm i6 is a latch or holding device 20 for holdingsaid lever arm in a set position, either in contact with the stopshoulder l8 or stop shoulder l9. This latch or holding device is in theform of alever mounted on a pin 2 I. Said lever at the inner end thereofis provided .with a locking pin 22 which passes through an opening inthe lever arm l6 and is adapted to enter a holeifla. associated with thestop shoulder l8 or a hole associated with the stop shoulder I9. Thislast-named hole is indicated at 23 in the drawings. to urge the holdingpin toward the radius block and will causeit to enter the hole when itis moved to a position in register therewith. This latch or holdingdevice may be readily pressed upon at its outer end for withdrawing thepin.

when the pin is seated in one of the holes with the leverarm against itsstop shoulder, then said lever arm is in a'iixed position relative tothe radius block and serves as a supporting means for' the radius block.

Associated with the radius block is a bending arm. 25. Said arm is fixedto a bending head 26.

Attached to the pivot stud I1 is a link-21. link is free to swing withthe pivot stud and extends beyond the periphery of the, radius block.

The bending head 26 is mounted on a pivot stud 28 attached to the outerend of the link 21. This bending head 26 is provided with a straightline face 29 which is provided with a recess extending lengthwisethereof. Said recess is curved A spring 24 serves This to conform to therecess 4 and serves as a seat for where said stop shoulder engages theside face of the link 21, then the straight face 29 of the bending headvis parallel to a line tangential of the curved face 2 at a point in theaxial line of the link 21, that is, a line passing centrally through thestud i1 and the stud 28. If there is no tube in the bender and the arm25 is turned in a counter-clockwise direction on the pivot stud 28, asviewed in Fig. 2, this stop shoulder will limit the movement to theposition shown in said figure, and as the link 21 turns about the studI1, the bending head will always maintain the same tangential positionrelative to the curved face 2 of the radius block. There is sufficientclearance between the face 29 of the bending head and the radius block 2so that said bending head does not contact with the radius block duringthe bending operation. The bending head is shaped so that the face 3|thereof is substantially at right angles to the face 29, and this face3i is so disposed relative to the centcrof the stud 28 that when the arm25 is swung to the position shown in Fig. 5, there is suiiicientclearance between this face 3i and the radius block so that the tube maybe inserted directly over the radius block and underneath the. bendinghead. Between the face 3| and the face 29 is a curved heel 29a providingsuflicient clearance so.that' when the link 21 is at right angles to thetube, the head may be swung into the position shown in Figures 1 and 2.When the bender is used on soft metal tubes, such as copper, suflicientpressure can be easily obtained when the parts are in the position shownin Fig. 1, by a pull upon the bending arm so as to bend the tube toconform to the radius block. The bending head will slide increment byincrement along the tube as it takes its curved form, and of course,will slide freely along the tube when it is curved to conform to theradius block. In bending steel tubes, it is desirable to compound thepressure force obtained by a manipulation of the bending arm and this isaccomplished in the following manner- The bending arm is positioned asshownin Fig. 9

relative to the link 21 and the link is turned so that it lies at anacute angle tothe straight axis of the tube which is to be curved. Thecenter of the curved portion 29a will contact with the tube,

, and this line of contact between. the tube and the bending head is atone side of a line passing centrally through. the pivotstud 28 and thepivot stud l1. When the arm 25 is pulled upon so that the head swingsabout the pivot stud 28 to the position shown in broken lines in Fig. 9,there is a cam action and a compounding of the forces bearing'on thetube; In other words, the center of the pivot stud 22 when moved to thedotted line position in Fig. 9, will cause the curved portion of thebending head to bear against the tube so tube and this portion forcedinto contact with the radius block by' a movement of the arm to thedotted line position. Thus it is that the bending head can be movedand'stepped along the tube so as to compound the force applied againstthe tube for the bending of the same. This enables very hard tubes to bereadily bent to conform to the radius block.

The bending head slides along the tube increment by increment and,curves the same to conform to the radius of the block. When the bendingarm has moved along the radius block through an arc-of 90 degreesorthereabouts, then the arm 25 is substantially parallel to and close tothe lever arm IS. The lever arm I6 is then shifted to a new set positionon the radius block. The

operator pressing on the holding device 20, re

leases the pin 22 from the radius block and shifts the lever arm Hi tothe position shown in Fig. 6. The holding device is then released andthis will lock the arm IS in this set position. The operator,

then continues to move the bending arm 25 in a clockwise direction andthis will complete the bending of the tube throughout an arc of 180degrees. To release the tube, the bending arm is turned so as to bringthe face 3| of the bending head into a position parallelto a tangent tothe curved face of the radius block. The' vise is opened and the tubemay be lifted by the lateral movement from the bender. This shifting ofthe lever arm l6 enables the two arms which are to be moved toward eachother for the bending of the tube to have a working movementsubstantially within an arc of 90 degrees. Inasmuch as this bender canbe placed on the tube by a lateral movement relative thereto, the bendermay be used for the shaping of protruding ends of tubes withoutdisturbing the tube already installed. It will be noted that the tubebender while strong and rugged is of few parts and the metal content isreduced to a minimum so that the bender can be handled in tight cornersand under difllcult installation conditions.-

It is obvious that many changes may be made in the details ofconstruction and the arrangement of the parts without departing from thespirit of the invention as set forth in the appended claims.

Having thus described the invention, what I claim as new and desire tosecure by Letters Patent, is

1. A tube bender comprising a radius block having the peripheral facethereof curved to conform to the curvature to which the tube is to ,bebent, a lever handle fixed to said block, a vise associated with theradius block for clamping the tube in a set position tangentially tosaid radius block, a link pivotally attached to the radius block at itscenter of curvature and projecting radially beyond the periphery of saidblock, a bending arm pivotally connected to sa d link at the outer endthereof. a head rigid with said arm and having a straight line faceadapted to engage the tube for bending the same and a stop shouldercarried by the head and disposed so as to contact with the side face ofsaid link for limiting the turning movement of the arm on said link whenthe face of the head reaches a position substantially at right angles tothe axial line of said link.

2. A tube bender comprising a radius block having the peripheral facethereof curved to conform to the curvature to which the tube is to bebent, a lever handle fixed to said block, a vise associated with theradius block for clamping the tube in a set position tangentially tosaid radius block, a link pivotally attached to the radius block at itscenter of curvature and projecting radially beyond the periphery of saidblock, a bending arm pivotally connected to said link at the outer endthereof, and a head rigid with said arm and having a straight line faceadapted to engage the tube for bending the same and means whereby saidlever handle may be shifted from one fixed position on said radius blockto another fixed position.

3. A tube bender comprising a radius block having the peripheral facethereof curved to conform to the curvature to which the tube is to bebent, a lever handle fixed to said block, a vise associated with theradius block for clamping the tube in a set position tangentially tosaid radius block, a link pivotally attached to the radius block at itscenter of curvature and projecting radially beyond the periphery of saidblock, a bending arm pivotally connected to said link at the outer endthereof, a head rigid with said arm and having a. straight line faceadapted to engage the tube for bending the same, said radius blockhaving an abutment shoulder, said vise including a clamping member, anda clamping screw carried thereby and adapted to engage the abutmentshoulder on the radius block, said radius block being cut away adjacentsaid shoulder so as to permit the clamping member to be quickly swung towide open position when the clamping screw is released from contact with.the shoulder.

4. A tube bender comprising a radius block having the peripheral facethereof curved to con form to the curvature'to which the tube is to bebent, a lever handle fixed to said block, a vise associated with theradius block for clamping the tube in a set position tangentially tosaid radius block, a link pivotally attached to the radius block at itscenter of curvature and projecting radially beyond the periphery of saidblock, a bending arm pivotally connected to said link at the outer endthereof, a head rigid with said arm and having a straight line faceadapted to engage the tube for bending the same. and a stop for limitingthe movement of said arm relative to said link so that said head ismaintained free from contact with the radius block.

5. A tube bender comprising a radius block having the peripheral facethereof curved to conform to the curvature to which the tube is to bebent, a lever handle fixed to said block, a vise associated with theradius block for clampin the tube in a setposition tangentially to sa dradius block, a link pivotally attached to the radius block at itscenter of curvature and projecting radially beyond the periphery of saidblock, a bending arm pivotally connected to said link at the outer endthereof, a head rigid with said arm and having a straight line faceadapted to engage the tube for bending the same, a stop for limiting themovement of said arm relative to said link so that said head ismaintained free from contact with the radius block, and means wherebysaid lever handle may be shifted from one fixed position on said radiusblock to another fixed position thereon.

6. A tube bender comprising a radius block having the peripheral facethereof curved to conform to the curvature to which the tube is to bebent, a lever handle fixed to said block, a vise associated with theradius block for clamping the tube in a set position tangentially tosaid radius block, a link pivotally attached to the radius block at itscenter of curvature and projecting radially beyond the periphery of saidblock, a bending arm pivotally connected to said link at the outer endthereof, a head rigid with said arm;

and having a straight line face adapted to engage the tube for bendingthe same, said straight line face, on said head at the inner end thereofmerg-' 7. A tube bender comprising a radius block,

having the peripheral face thereof curved to conform to the curvature towhich the tube is to be bent, a lever handle fixed to said block, a viseassociated with the radius block for clamping the tube in a set positiontangentially-to said radius block, a link pivotally attached to theradius block at its center of curvature and projecting radially beyondthe periphery of said block, a bending arm pivotally connected to-saidlink at the outer end thereof, a head rigid with said arm and having astraightline face adapted to engage the tube for bending the same, saidstraight line face on said head at the inner end thereof merging intothe curved face disposed so as to contact with a straight portion of thetube at one side of the center line of the link for compounding thebending forceapplied to the tube when pressure is applied to the bendingarm, and a stop for limiting the movement of said bending arm relativeto said link so that said head is maintained free from contact with theradius block at all times.

8. A tube bender comprising a radius block having the peripheral facethereof curved to conform to the curvature to which the'tube is to bebent, a hand lever fixed to said block and shiftable to different setpositionsthereon, a vise associated with the radius block for clamping atube in set position thereon, said vise having a clamping member, andmeans operating to hold said clamping member in contact with the tube, alink pivotally attached to the radius block at the center ,of curvatureand projecting radially beyond the periphery of said block, a bendingarm pivotally connected to said link at the outer end thereof, a headrigid with said arm and having a straight line face adapted to engagethe tube for bending the same, said peripheral face of the radius blockand said straight line face of the bending head being recessed toconform to the tube operated upon.

9. A tube bender comprising a radius block having the peripheral facethereof curved to conform to the curvature to which the tube is to bebent, a hand lever, fixed to said block and shiftable to different setpositions thereon, a vise associated with the radius block for clampinga tube in set position thereon, said vise having a arm pivotallyconnected to said link at the outer end thereof, a head rigid with saidarm and having a straight line face adapted to engage the tube forbending the same, said peripheral face of the radius block and saidstraight line face of the bending head being recessed to conform to thetube operated upon, and a stop for limiting the movement of the bendingarm relative to said link so that the bending head is maintained freefrom contact with the radius block at all times. I

10. -A tube bendercomprising a radius block having the peripheral facethereof curved to conform to the curvature to which the tubeis to bebent, at hand lever fixed to said block and shiftable to different setpositions thereon, a vise associated with the radius block for clampinga tube in set position thereon,said vise having a clamping member andmeans operating to hold said clamping member in contact with the tube, alink pivotally attached to the radius block at the center of curvatureand projecting radially beyond the periphery of said block, a bendingarm pivotally connected to said link at the outer end thereof, a headrigid with said arm and having a straight line face adapted to engagethe tube for bending the same, said peripheral face of the radius blockand said straight line face of the bending head being recessed toconform to the tube operated upon, said bending head at the inner endthereof having a curved-face disposed so as to contact with the straightportion of the tube at one side.of'the link whereby the force exertedupon the tube may be compounded.

11. A tube bender comprising a radius block having the peripheral facethereof curved to conform to the curvature to which the tube is tobebent, a hand lever fixed to said block and shiftable to different setpositions thereon, a viseassociated with the radius block for clamping atube inset position thereon, said vise having a clamping member andmeans operating to hold said clamping member in contact with the tube, alink pivotally attached to the radius block at the center of curvatureand projecting radially beyond the periphery of said block, a bendingarm pivotally connected to said link atthe outer end thereof, a headrigid with said arm and having a straight line face adapted to engagethe tube for bending the same, said peripheral face of the radiusblockand said straight line face of the bending head being recessed toconform to the tube operated upon, said bending head at the inner endthereof having a =curved face disposed so as to contact with thestraight portion of the tube at one side of the link whereby the forceexerted upon the tube may be compounded, and a stop for limitingthemovement of the bending arm relative to the link whereby said bendinghead is maintained at all times free from contact with the radius block.

ARTHUR L. PARKER.

